Date: Tue, 17 Aug 2004 10:10:45 -0700 From: Julian Elischer <julian@elischer.org> To: =?ISO-8859-2?Q?S=B3awek_=AFak?= <szak@era.pl> Cc: freebsd-current@freebsd.org Subject: Re: Deadlocks with recent SMP current Message-ID: <41223C15.7050305@elischer.org> In-Reply-To: <86y8kfqcp8.fsf@thirst.unx.era.pl> References: <20040813121208.M31181@cvs.imp.ch> <86y8kfqcp8.fsf@thirst.unx.era.pl>
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Sławek Żak wrote: > Martin Blapp <mb@imp.ch> writes: > > >>Hi, >> >>Since yesterday I'm getting complete deadlocks. This time unrelated >>the servers are nor loaded at all, the just freeze after a while. >>No break into DDB possible at all. > > > Despite the numerous reports of current problems I'm running 5.2-CURRENT for > 12 days now without a glitch. Tested overnight with 2 buildworlds running > with -j8. It's a 2 processor Xeon server with 4BSD scheduler. Just my .02 > euro. > > Another thing is bothering me. In top I see: > > CPU states: 16.2% user, 0.0% nice, 2.5% system, 1.0% interrupt, 80.3% idle > Mem: 254M Active, 605M Inact, 254M Wired, 16K Cache, 112M Buf, 2622M Free > Swap: 4096M Total, 4096M Free > > PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND > 37033 mysql 20 0 265M 178M kserel 0 610:59 124.37% 124.37% mysqld > > > MySQLd is running with libpthread and can go up to 400% without > significantly afecting the idle percentage shown by top. I don't see how I > could fit 400% into 20% on those two suckers, therefore I ask :) > > /S Cpu percentage use is broken for pthread applications.. it's almost impossible to work out the right way of doing it due to the nature of M:N threading where there is no fixed rule as to which user thread is run by which kernel thread. I have ideas but it will probably have to be an aggreagate cpu% for the thread group, divided by the number of kernel threads in the group.
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